1. Field of the Invention
The present invention relates to a disk drive, and, more particularly, to a disk tray with a resonator to reduce noise and vibration, such as noise generated during rotation of a disk.
2. Description of the Related Art
FIG. 1 is a perspective view of a conventional disk drive. In general, disk drives are apparatuses for either recording information on a recording surface of a disk having concentric tracks, or reading information from the recording surface. Referring to FIG. 1, the disk drive records data on the recording surface of a disk 60 rotating with a linear velocity, or reads data from the recording surface of the disk 60, by using a data recording/reproducing unit, such as optical pickup device 40, that slides in a radial direction with respect to the disk 60.
The conventional disk drive typically includes a disk tray 10 on which a disk is mounted and loaded, a disk driving portion 20 to rotate the disk 60, a disk chucking apparatus 30 with a chuck plate 31 and a disk chuck 32, and an optical pickup device driving portion 50. The disk tray 10 has a window 11 penetrating the disk tray 10 to facilitate operation of the disk chucking apparatus 30 and the optical pickup device 40.
To accurately record or read data on or from the recording surface of the disk 60, the light beam emitted from the optical pickup device 40 must be accurately incident on a track of the recording surface of the disk 60, and a predetermined angle is always maintained between the recording surface and the optical axis of the light beam emitted from the optical pickup device 40. However, vibration is generated due to the rotating disk 60 that deteriorates the recording and reproduction feature of the disk drive. Further, as the rotation speed of the disk drive increases, the vibration generated during the rotation of the disk 60 impacts reliability in recording and reproduction of data. Also, noise generated during the rotation of the disk 60 is unpleasant to users. Accordingly, reducing or removing the noise and vibration is very important.
The noise and vibration generated during the rotation of the disk 60 result from friction between a surface of the disk 60 and surrounding air, a difference in pressure around the disk 60, collision of air with the rotating disk 60 and the disk tray 10 and an inner surface of the disk drive, and turbulence formed around the disk 60.
The conventional technologies to reduce noise and vibration in disk drives are described below.
Korean Patent Publication No. 2000-75152 discloses technologies to reduce noise and vibration by filling gaps, which contribute to the generation of noise, between constituent elements in a disk drive with a sound shield or a sound absorbing member so that the noise is not discharged to the outside, or by forming grooves at predetermined intervals in a portion of a chucking plate of a disk chucking apparatus corresponding to the outer circumferential surface of a disk (i.e., at the outer circumference of the chucking plate), using the muffler effect technology of the automobile industry.
Also, Korean Patent Publication No. 2001-16753 discloses a technology to reduce noise and vibration that uses an auto-balancing method of inserting balls in a plurality of races provided in a turntable of a disk and moving the balls in a radial direction by the centrifugal force generated during rotation of the turntable to compensate for eccentricity of the turntable.
Also, Korean Patent Publication No. 1999-80545 discloses a noise reduction apparatus to reduce, during rotation of the disk, air resistance due to the shape of the profile of a disk, air friction on the upper and lower surfaces of the disk, collision of air with a wall surface due to a separation phenomenon at an outer edge of the disk, and noise due to the flow of turbulence at a high speed. In the noise reduction apparatus, a plurality of blades are installed on the upper surface of the disk tray that are separated a predetermined distance, or a groove or dimple having a screw or vortex shape is formed thereon. Thus, the speed gradient at a boundary surface on the upper and lower surface of the disk is removed and collision of the high speed air flow at the leading end of the disk is prevented so that noise and vibration due to the flow of the high speed turbulence are reduced.
However, the conventional technologies focus only on the reduction of a level of the overall noise. Thus, a highly effective noise reduction effect can be obtained by not only reducing the level of the overall noise, but also by reducing or removing the most dominant noise frequency of the disk drive.